Chemokines in cerebrospinal fluid correlate with cerebral metabolite patterns in HIV-infected individuals.

Chemokines influence HIV neuropathogenesis by affecting the HIV life cycle, trafficking of macrophages into the nervous system, glial activation, and neuronal signaling and repair processes; however, knowledge of their relationship to in vivo measures of cerebral injury is limited. The primary objective of this study was to determine the relationship between a panel of chemokines in cerebrospinal fluid (CSF) and cerebral metabolites measured by proton magnetic resonance spectroscopy (MRS) in a cohort of HIV-infected individuals. One hundred seventy-one stored CSF specimens were assayed from HIV-infected individuals who were enrolled in two ACTG studies that evaluated the relationship between neuropsychological performance and cerebral metabolites. Concentrations of six chemokines (fractalkine, IL-8, IP-10, MCP-1, MIP-1ß, and SDF-1) were measured and compared with cerebral metabolites individually and as composite neuronal, basal ganglia, and inflammatory patterns. IP-10 and MCP-1 were the chemokines most strongly associated with individual cerebral metabolites. Specifically, (1) higher IP-10 levels correlated with lower N-acetyl aspartate (NAA)/creatine (Cr) ratios in the frontal white matter and higher MI/Cr ratios in all three brain regions considered and (2) higher MCP-1 levels correlated with lower NAA/Cr ratios in frontal white matter and the parietal cortex. IP-10, MCP-1, and IL-8 had the strongest associations with patterns of cerebral metabolites. In particular, higher levels of IP-10 correlated with lower neuronal pattern scores and higher basal ganglia and inflammatory pattern scores, the same pattern which has been associated with HIV-associated neurocognitive disorders (HAND). Subgroup analysis indicated that the effects of IP-10 and IL-8 were influenced by effective antiretroviral therapy and that memantine treatment may mitigate the neuronal effects of IP-10. This study supports the role of chemokines in HAND and the validity of MRS as an assessment tool. In particular, the findings identify relationships between the immune response-particularly an interferon-inducible chemokine, IP-10-and cerebral metabolites and suggest that antiretroviral therapy and memantine modify the impact of the immune response on neurons.

Incidence of post-dural puncture headache in research volunteers.

OBJECTIVE: To determine the frequency and risk factors of post-dural puncture headache (PDPH) in research volunteers. BACKGROUND: Despite increasing interest in measuring cerebrospinal fluid (CSF) biomarkers to investigate disease pathogenesis and diagnosis, previous case series have evaluated lumbar puncture (LP) safety only in clinical care. PDPH is a common complication after LP. METHODS: We determined the frequency of PDPH in neurologically unselected HIV seropositive and seronegative adults volunteering for research, as well as the variables associated with the development of PDPH. Variables studied were body mass index (BMI), HIV serostatus, volume of CSF removed, number of previous LPs, use of pre-medication, LP position, lumbar space, number of needle passes, whether or not aspiration was used, CSF white blood cell counts, CSF red blood cell counts, CD4 count, CD4 nadir, CSF HIV viral load, plasma HIV viral load, and race. RESULTS: Of 675 LPs performed over 1 year, headache developed in 38 (5.6%; 95% CI 4.2, 7.1). Most PDPH (92%) resolved spontaneously or with conservative medical management; 3 required epidural blood patch. Greater headache risk was associated with lower BMI (BMI ≤25 vs >25) (OR 3.3; CI 95% 1.5, 7.0; P = .001) and less prior LP experience (previous LPs ≤2 vs >2) (OR 2.1; CI 95% 1.1, 4.1; P = .03). PDPH was not significantly (P > .05) related to HIV serostatus, CSF volume, or gender. CONCLUSION: In this study, where tolerance to risk was low because LPs were done for research rather than clinical purposes and healthy controls were included, adverse effects were mild and self-limited.

Family history of dementia predicts worse neuropsychological functioning among HIV-infected persons.

HIV-negative individuals with a family history of dementia (FHD) are more likely to develop dementia than those without FHD. Whether FHD increases risk for neuropsychological (NP) impairment in HIV+ persons is unknown. As part of a multisite study into HIV-associated neurocognitive disorders (HAND), the authors captured FHD with a free-response, self-report question, and assessed NP performance with a comprehensive battery of tests. The authors examined HIV+ persons with (N=190) and without (N=916) self-reported FHD. Despite the fact that the FHD group had factors typically associated with better NP performance (e.g., higher CD4 counts and estimated verbal IQ), persons with FHD had significantly worse NP ability than those without FHD as measured by a Global Deficit Score. Thus, FHD appears to be a risk factor for HAND; the mechanism(s) underlying how FHD contributes to NP impairment among HIV+ persons warrants study.

Cerebrospinal fluid human immunodeficiency virus viral load in patients with neurosyphilis.

Syphilis is a frequent coinfection with human immunodeficiency virus (HIV). Whereas systemic syphilis infection increases plasma HIV RNA levels (viral load; VL), effects of syphilis on cerebrospinal fluid (CSF) VL are unknown. We hypothesized that intrathecal immune activation in neurosyphilis would selectively increase CSF VL in coinfected patients. In this study, HIV-infected research subjects (N = 225) were categorized into three groups based on serum rapid plasma reagin (RPR), microhemaglutination for Treponema pallidum (MHA-TP) MHA-TP, and CSF VDRL: 23 with neurosyphilis (NS+; reactive serum RPR and MHA-TP and positive CSF VDRL); 42 with systemic syphilis but not neurosyphilis (Syph+; reactive serum RPR and MHA-TP; negative CSF VDRL), and 160 without syphilis (Syph-; nonreactive serum RPR). Plasma and CSF HIV VL were quantified by reverse transcriptase-ploymerase chain reaction (RT-PCR) (Amplicor, Roche) in log(10) copies/ml. To adjust for covariates previously shown to influence CSF HIV VL (i.e., plasma VL, CD4, pleocytosis, and highly active antiretroviral therapy [HAART]), multivariable linear regression was used. Lumbar punctures (LP) done for research purposes diagnosed 23 with neurosyphilis; most (83%) of these reported prior syphilis treatment. Among subjects with detectable plasma VL, CSF VL was highest in NS+, followed by Syph+ and Syph- (P =.006). This relationship was independent of the level of plasma VL or CSF pleocytosis. By contrast, among subjects with undetectable plasma HIV VL, CSF VLs were similar in the three syphilis subgroups (P = .50). Neurosyphilis may amplify intrathecal HIV replication, possibly through immune activation that persists even after syphilis treatment. Because elevated CSF VL is associated with subsequent neurocognitive decline, future studies should evaluate the impact of neurosyphilis on the course of central nervous system (CNS) HIV infection.

Informing Informed Consent for HIV Research.

"Respect for Persons" is an ethical principle demonstrated through the informed consent process. Participants at a large HIV research center were surveyed to identify important aspects of the consent process. Persons with and without HIV (n = 103) completed a short pre/post questionnaire with both open-ended and forced choice response options. Qualitative analysis resulted in eleven themes about the most important consent elements which did not differ by HIV serostatus. Overall, participants rated the informed consent content and presentation by research staff as "extremely informative" and found the consent information to be "extremely consistent" with their study experience. Study results support the value of an interactive process and can be used to inform the design of a standardized, digital consent process.

Role of metabolic syndrome components in human immunodeficiency virus-associated stroke.

Metabolic syndrome (MetS) is a cluster of risk factors, including elevated mean arterial pressure (MAP), atherogenic dyslipidemia (elevated triglycerides [TRG]), abdominal obesity (increased body mass index [BMI]), glucose intolerance (elevated glucose [GLU]), and prothrombotic/inflammatory state (increases in uric acid [UA]), that are associated with increased risk of cerebrovascular disease. We studied if an association existed between MetS components and human immunodeficiency virus (HIV)-associated cryptogenic strokes-those not caused by HIV complications, endocarditis, or stimulant abuse. We performed a retrospective case-control study. Eleven cryptogenic strokes were identified from 2346 HIV-infected (HIV+) participants. Each case was matched by age, sex, and date of stroke diagnosis to five HIV+ controls without stroke. Nonparametric stratified Wilcoxon ranked sum tests with subsequent mixed effect logistic regression determined the influence of each MetS component on HIV-associated cryptogenic stroke. Although each MetS component appeared higher for HIV+ cases with cryptogenic strokes than HIV+ controls, only MAP (odds ratio [OR] = 5.70, 95% confidence interval [CI] = 1.15-28.3) and UA (OR = 1.88, 95% CI = 1.06-3.32) were statistically different. A significantly higher percentage of HIV-associated cryptogenic stroke cases met criteria for MetS (4/11 = 36%) compared to HIV+ controls (6/55 = 11%). This observational study suggests a possible role for MetS components in HIV+ cryptogenic stroke cases. Although MetS is defined as a constellation of disorders, elevated hypertension and hyperuricemia may be involved in stroke pathogenesis. Reducing MetS component levels in HIV+ patients could therefore protect them from subsequent stroke.

Human immunodeficiency virus protease inhibitors and risk for peripheral neuropathy.

OBJECTIVE: Two recent analyses found that exposure to protease inhibitors (PIs) in the context of antiretroviral (ARV) therapy increased the risk for distal sensory polyneuropathy (DSPN) in subjects with human immunodeficiency virus (HIV) infection. These findings were supported by an in vitro model in which PI exposure produced neurite retraction and process loss in dorsal root ganglion sensory neurons. Confirmation of peripheral nerve toxicity with PIs could substantially limit their long-term use in highly active ARV therapy. METHODS: We evaluated current and past exposure to PIs as a risk factor for DSPN in 1,159 HIV-infected individuals enrolled in a large, prospective, observational, multicenter study. Signs of DSPN were ascertained by neurological examination. Subjects were grouped into categories according to past and current exposure to any ARV and to PIs. We included disease indicators such as nadir CD4, plasma viral load, and duration of HIV infection, as well as advancing age and exposure to dideoxynucleoside ARVs in multivariate models. RESULTS: In univariate analyses, both past and current PI exposure significantly increased the risk for DSPN. However, after adjusting for previously validated concomitant risk factors in multivariate models, none of the PI exposure groups was more likely to have DSPN than ARV naive subjects. A secondary evaluation of duration of PI use and exposure to individual PI drugs was similarly nonsignificant in multivariate models, except for small effects of amprenavir and lopinavir. INTERPRETATION: Evaluation of concomitant risks for HIV DSPN suggests that the independent risk attributable to PIs, if any, is small. This risk must be weighed against the important role of PIs in modern ARV therapy regimens.

Validation of the CNS Penetration-Effectiveness rank for quantifying antiretroviral penetration into the central nervous system.

OBJECTIVE: To evaluate whether penetration of a combination regimen into the central nervous system (CNS), as estimated by the CNS Penetration-Effectiveness (CPE) rank, is associated with lower cerebrospinal fluid (CSF) viral load. DESIGN: Data were analyzed from 467 participants who were human immunodeficiency virus (HIV) seropositive and who reported antiretroviral (ARV) drug use. Individual ARV drugs were assigned a penetration rank of 0 (low), 0.5 (intermediate), or 1 (high) based on their chemical properties, concentrations in CSF, and/or effectiveness in the CNS in clinical studies. The CPE rank was calculated by summing the individual penetration ranks for each ARV in the regimen. RESULTS: The median CPE rank was 1.5 (interquartile range, 1-2). Lower CPE ranks correlated with higher CSF viral loads. Ranks less than 2 were associated with an 88% increase in the odds of detectable CSF viral load. In multivariate regression, lower CPE ranks were associated with detectable CSF viral loads even after adjusting for total number of ARV drugs, ARV drug adherence, plasma viral load, duration and type of the current regimen, and CD4 count. CONCLUSIONS: Poorer penetration of ARV drugs into the CNS appears to allow continued HIV replication in the CNS as indicated by higher CSF HIV viral loads. Because inhibition of HIV replication in the CNS is probably critical in treating patients who have HIV-associated neurocognitive disorders, ARV treatment strategies that account for CNS penetration should be considered in consensus treatment guidelines and validated in clinical studies.

Lopinavir concentrations in cerebrospinal fluid exceed the 50% inhibitory concentration for HIV.

INTRODUCTION: Lopinavir (LPV) is highly bound to plasma proteins and is a substrate for active drugs transporters, which may greatly limit the access of LPV to the central nervous system (CNS). However, even low lopinavir concentrations may be sufficient to inhibit HIV replication. Prior anecdotal reports indicated that lopinavir concentrations were below detection in cerebrospinal fluid (CSF). METHODS: LPV was measured by liquid chromatography/mass spectrometry in 31 CSF-plasma pairs from 26 HIV-infected individuals who were taking LPV-containing antiretroviral regimens. The lower limit of quantification was 3.7 microg/l. RESULTS: Seven of the sample pairs had very low plasma (and CSF) LPV concentrations, with a mean estimated plasma trough of 274 microg/l (range, < 3.7 to 608; typical trough values approximately 4000 microg/l), suggesting poor recent adherence. In the remaining 24 sample pairs, the median LPV concentration was 5889 microg/l [interquartile range (IQR), 4805-9620] and all CSF samples had measurable LPV concentrations: median 17.0 microg/l (IQR, 12.1-22.7). The median CSF-plasma ratio was 0.23% (range, 0.12-0.75). All CSF concentrations in these samples were more than double the 50% inhibitory concentration for wild-type HIV virus. CONCLUSIONS: In patients with typical plasma levels of LPV, the drug is detectable in the CSF at concentrations that exceed those needed to inhibit HIV replication. Despite being > 98% bound to plasma proteins, LPV penetrates into the CNS and may contribute to the control of HIV in this potential reservoir.

The effects of hepatitis C, HIV, and methamphetamine dependence on neuropsychological performance: biological correlates of disease.

OBJECTIVE: To determine the effects of hepatitis C virus (HCV) infection on neuropsychological (NP) performance. DESIGN: Cross-sectional analysis of a prospectively enrolled cohort. METHODS: A total of 239 HIV-seropositive and 287 HIV-seronegative subjects enrolled in prospective cohort studies at a single center. Subjects underwent standardized assessments, including comprehensive neuropsychological testing, substance use inventory neuromedical examination, venipuncture, and lumbar puncture. HCV antibody was measured in serum. In seropositive individuals, HCV RNA was measured in plasma and cerebrospinal fluid (CSF). RESULTS: HCV-seropositive subjects performed worse on neuropsychological testing and were almost twice as likely to be diagnosed as globally impaired, compared with those who were HCV seronegative. In a multivariate analysis, HCV, HIV, and methamphetamine dependence were independently associated with worse performance, even after adjusting for Centers for Disease Control stage and antiretroviral use. HCV-RNA levels in plasma were higher in those with memory, but not global, impairment. In cerebrospinal fluid, HCV RNA was below 100 copies/ml in all specimens. In HIV-infected subjects, HCV was associated with higher levels of HIV RNA in CSF, but not in plasma. HCV was also associated with higher levels of monocyte chemotactic protein 1, TNF-alpha, and soluble TNF receptor II. HCV-seropositive subjects did not appear to have advanced liver disease. CONCLUSIONS: HIV, HCV, and methamphetamine independently injure the central nervous system, leading to global neuropsychological impairment. HCV may injure the brain by viral or immune-mediated mechanisms. HCV-associated brain injury may be preventable or reversible because HCV infection is potentially curable.

CCR2 polymorphisms affect neuropsychological impairment in HIV-1-infected adults.

CCR2 is a minor coreceptor for human immune deficiency virus-1 (HIV-1) and its impact on HIV-1-related neuropsychological impairment (NPI) remains unknown. We studied the impact of CCR2-V64I polymorphisms on the development of NPI in 121 HIV-1 patients. The CCR2-64-I allele was associated with rate of progression to NPI when measured from the first study visit (Log Rank p=0.01) or from the estimated time of seroconversion (p=0.02). CCR2-V64I was not associated with plasma or CSF HIV-1 RNA load, suggesting that the impact of CCR2 on neuropathogenesis may involve alterations in inflammatory responses within the CNS rather than a direct impact on viral entry or replication.

The monocyte chemotactic protein-1 -2578G allele is associated with elevated MCP-1 concentrations in cerebrospinal fluid.

Because monocyte chemotactic protein (MCP)-1 is an important cofactor in HIV neuropathogenesis, we investigated the relationship between MCP-1 genotype and expression in cerebrospinal fluid (CSF). We evaluated a genetic polymorphism in the MCP-1 promoter at position -2578 (alternatively designated -2518) in 98 HIV-infected subjects who had contemporaneously collected plasma and CSF. CSF MCP-1 levels were highest in the G/G genotype group, intermediate in the G/A group, and lowest in the A/A group. MCP-1 levels in plasma only differed by genotype after adjusting for HIV-related factors. Our findings suggest that this MCP-1 promoter polymorphism influences HIV neuropathogenesis by regulating MCP-1 protein expression in the central nervous system (CNS).

Portable lactate analyzer for measuring lactate in cerebrospinal fluid (CSF) and plasma - method-comparison evaluations.

UNLABELLED: Increased plasma lactate levels can indicate the presence of metabolic disorders in HIV infected individuals. OBJECTIVE: To determine whether a portable analyzer is valid for measuring cerebrospinal fluid (CSF) and plasma lactate levels in HIV infected individuals. METHOD: CSF and plasma were collected from 178 subjects. Samples tested by the Accutrend portable analyzer were compared to those tested by a reference device (SYNCHRON LX 20). RESULTS: The portable analyzer had in plasma sensitivity of 0.95 and specificity 0.87. For CSF the specificity was 0.95; the sensitivity 0.33; the negative predictive value was 95% and the positive predictive value 33%. CONCLUSIONS: These findings support the validity of the portable analyzer in measuring lactate concentrations in CSF that fall within the normal range. The relatively poor positive predictive value indicates that a result above the reference range may represent a "false positive test", and should be confirmed by the reference device before concluding abnormality.

Portable lactate analyzer for measuring lactate in cerebrospinal fluid (CSF) and plasma ? method-comparison evaluations / Analisador portátil para dosar lactato no líquido cefalorraquidiano e plasma ? comparação de método

Increased plasma lactate levels can indicate the presence of metabolic disorders in HIV infected individuals. Objective: To determine whether a portable analyzer is valid for measuring cerebrospinal fluid (CSF) and plasma lactate levels in HIV infected individuals. Method: CSF and plasma were collected from 178 subjects. Samples tested by the Accutrend® portable analyzer were compared to those tested by a reference device (SYNCHRON LX® 20). Results: The portable analyzer had in plasma sensitivity of 0.95 and specificity 0.87. For CSF the specificity was 0.95; the sensitivity 0.33; the negative predictive value was 95% and the positive predictive value 33%. Conclusions: These findings support the validity of the portable analyzer in measuring lactate concentrations in CSF that fall within the normal range. The relatively poor positive predictive value indicates that a result above the reference range may represent a “false positive test”, and should be confirmed by the reference device before concluding abnormality. .

O aumento da concentração plasmática dos níveis de lactato pode indicar a presença de distúrbios metabólicos em indivíduos infectados pelo HIV. Objetivo: Determinar a validade do analisador portátil para quantificar os níveis de lactato no líquido cefalorraquidiano (LCR) e plasma em indivíduos infectados. Método: LCR e plasma foram coletados de 178 participantes. As amostras testadas com o analisador portátil Accutrend® e os resultados comparados com aqueles obtidos com o equipamento de referência (SYNCHRON LX® 20). Resultados: O analisador portátil teve, no plasma, sensibilidade de 0,95 e especificidade 0,87. No LCR a especificidade foi 0,95; a sensibilidade 0,33; o valor preditivo negativo foi de 95% e o valor preditivo positivo 33%. Conclusões: Estes dados suportam a validade dos resultados do analisador portátil em concentrações de lactato dentro da faixa normal. Os valores preditivos positivos relativamente baixos indicam que um resultado acima da faixa de referência pode representar um resultado “falso positivo”. .

Role of metabolic syndrome components in HIV-associated sensory neuropathy.

OBJECTIVES: Sensory neuropathy is a common peripheral nerve complication of HIV infection and highly active antiretroviral therapy. Metabolic syndrome (MetS), a cluster of risk factors for atherosclerosis and microvascular disease, is associated with sensory neuropathy in HIV-uninfected (HIV-negative) persons. We examined whether MetS or its components predispose individuals to HIV-associated sensory neuropathy (HIV-SN). DESIGN: From a prospective multicenter cohort of 1556 HIV-positive patients, a subgroup (n = 130) with fasting laboratory tests and sensory neuropathy assessment was selected. METHODS: Sensory neuropathy was defined by symmetrically decreased reflexes or sensation loss in the legs. MetS was defined by presence of at least three risk factors: mean arterial pressure of at least 100 mmHg; triglycerides (TRGs) of at least 150 mg/dl and high-density lipoprotein cholesterol of less than 40 mg/dl for male patients, less than 50 mg/dl for female patients; body mass index of more than 25 kg/m; plasma glucose (GLU) of at least 100 mg/dl and self-reported diabetes mellitus type 2. Multivariate logistic regression examined the association between HIV-SN and MetS. RESULTS: After controlling for HIV-SN risk factors such as age, CD4 current, length of HIV infection, use of dideoxynucleoside reverse transcriptase inhibitors and protease inhibitors, MetS was not associated with HIV-SN (P = 0.72). However, when each MetS component was assessed, elevated TRG was a significant risk factor for HIV-SN. From the larger cohort, both diabetes mellitus type 2 (odds ratio = 1.4, P < 0.01) and elevated TRG (odds ratio = 1.4, P = 0.01) were risk factors for HIV-SN. CONCLUSION: The risk of HIV-SN was increased for diabetes mellitus type 2 and elevated TRG but not for other MetS components. Both increase the risk of sensory neuropathy in HIV-populations, but the mechanism(s) remains unclear.

The role of cohort studies in drug development: clinical evidence of antiviral activity of serotonin reuptake inhibitors and HMG-CoA reductase inhibitors in the central nervous system.

BACKGROUND: Effective antiretroviral therapy (ART) has reduced the incidence of HIV-associated neurocognitive impairment (HNCI) but its prevalence remains high. Clinical trials have yet to identify a consistently effective treatment for HNCI, other than ART, but in vitro data support that some drugs approved by the Food and Drug Administration (FDA) for other indications might benefit individuals with HNCI. Some of these drugs, such as serotonin reuptake inhibitors (SRIs) and HMG-CoA reductase inhibitors (statins), may do so by reducing HIV replication in the CNS and are already widely used by HIV-infected individuals. METHODS: Six-hundred fifty-eight HIV-infected participants of the CHARTER cohort had a baseline assessment, which included comprehensive neuropsychological (NP) testing and HIV RNA measurements in plasma and cerebrospinal fluid (CSF). Four-hundred sixty-seven (71%) subjects used ART, 195 (30%) used SRIs, and 63 (10%) used statins. RESULTS: SRI users were less likely to have HIV RNA levels in CSF above 50 copies (c)/mL (29 vs. 37% in non-SRI users, OR 0.69, p = 0.05). This association was most evident for three of the seven SRIs (citalopram, sertraline, and trazodone, or "antiviral" SRIs, combined 25 vs. 38% in non-SRI users, OR 0.56, p = 0.01) and was strongest in those not taking concomitant ART (61 vs. 83%, OR 0.31, p = 0.01). "Antiviral" SRI users also performed better on NP tests (median global deficit score 0.37 vs. 0.47, p = 0.04). Statin users were also less likely to have HIV RNA levels in CSF above 50 c/mL (16 vs. 37%, p < 0.001) but, in contrast to SRIs, the association was strongest in those taking ART (2 vs. 18%, p < 0.001). Statin use was not associated with better NP performance. Multivariate analyses indicated that the use of "antiviral" SRIs-but not statins-was associated with undetectable HIV RNA levels in CSF and better NP performance. CONCLUSIONS: SRIs may reduce HIV replication in CSF and improve NP performance. This was particularly true for three SRIs-supporting differences in antiviral efficacy between drugs-in individuals who were not taking ART. In contrast, statins were not associated with lower HIV replication in CSF in multivariate analyses and were not associated with better NP performance. These analyses support the value of large observational cohort studies in identifying FDA-approved drugs that may be worth further investigation.

Valproic acid does not affect markers of human immunodeficiency virus disease progression.

Valproic acid (VPA) reduces latent human immunodeficiency virus (HIV) reservoirs by activating resting CD4+ cells. This retrospective case-control study (n = 30) examined effects of VPA on markers of HIV progression. VPA was not associated with changes in cerebrospinal fluid viral loads (VL), plasma VL, or neuropsychological performance. VPA patients had a trend towards lower CD4+ cells (P = .08) at follow-up. Concurrent antiretrovirals did not alter these relationships. VPA does not induce viremia or promote disease progression and may be safe for clinical intervention.

Markers of macrophage activation and axonal injury are associated with prospective memory in HIV-1 disease.

OBJECTIVE: To use clinical specimens to better understand the neuropathogenesis of prospective memory (ProM) functioning in persons with HIV-1 infection. BACKGROUND: Emergent evidence suggests that HIV-1 is associated with impaired ProM, but the underlying neuropathophysiology of this deficit is not known. METHODS: Thirty-five nondemented subjects with HIV-1 infection completed measures of both ProM (ie, memory for future intentions) and retrospective memory (RM; ie, memory for past episodes). A panel of biomarkers reflecting several possible neuropathogenic mechanisms of HIV was measured in plasma and cerebrospinal fluid, including HIV-1 RNA, total tau, monocyte chemoattractant protein-1 (MCP-1), soluble receptor for tumor necrosis factor type II, and fibroblast growth factor 1. RESULTS: After controlling for antiretroviral therapy and CD4 lymphocyte count, higher levels of MCP-1 in plasma, and soluble receptor for tumor necrosis factor type II and tau in cerebrospinal fluid were associated with ProM, but not RM. Markers of astrocytosis, growth factor depletion, and HIV-1 replication did not predict either ProM or RM. CONCLUSIONS: ProM impairment in HIV-1 may be dissociable from RM, perhaps reflecting specific neuropathogenic mechanisms of macrophage activation and axonal injury.

Relationship of antiretroviral treatment to postmortem brain tissue viral load in human immunodeficiency virus-infected patients.

Human immunodeficiency virus (HIV)-1 invades the central nervous system (CNS) soon after infection and is partially protected there from host immunity and antiretroviral drugs (ARVs). Sanctuary from highly active antiretroviral therapy (HAART) in the CNS could result in ongoing viral replication, promoting the development of drug resistance and neurological disease. Despite the importance of these risks, no previous study has directly assessed HAART's effects on brain tissue viral load (VL). The authors evaluated 61 HIV-infected individuals for whom both histories of HAART treatment and postmortem brain tissue VL measurements were available. Two groups were defined based on HAART use in the 3 months prior to death: HAART(+) subjects had received HAART, and HAART(-) subjects had not received HAART. HIV RNA was quantified in postmortem brain tissue (log10 copies/10 microg total tissue RNA) and antemortem plasma (log10 copies/ml) by reverse transcriptase-polymerase chain reaction (RT-PCR). Brain tissue VLs were significantly lower among HAART(+) subjects compared to HAART(-) subjects (median 2.6 versus 4.1; P= .0007). These findings suggest that despite the limited CNS penetration of many antiretroviral medications, HAART is at least partially effective in suppressing CNS viral replication. Because some HAART regimens may be better than others in this regard, regimen selection strategies could be used to impede CNS viral activity, limit neuronal dysfunction, and prevent or treat clinical neurocognitive disorders in HIV-infected patients. Furthermore, such strategies might help to prevent the development of ARV resistance.